This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Stroke With Transfusions Changing To Hydroxyurea (Switch): A Phase III Randomized Clinical Trial To Compare Standard Theraphy (Erythrocyte Transfusions With IRon Chelation) With Alternative Therapy (Hydroxyurea With Phlebotomy) For The Prevention Of Secondary Stroke And The Management Of Iron Overload in Pediatric Subjects With Sickle Cell Anemia And Previous Stroke